Cathodic Stripping

The resulting solution of nickel chloride is electrolysed with graphite anodes and nickel strip cathodes, and yields a very pure metal.1... 

Stripped cathodes are automatically sent through a weigher to the stock yard by a chain conveyor. 

Prior to introduction of the autostrippers over the period 1995 to 1999, the cathodes were manually stripped. Cathode auto-stackers of Kidd design were introduced in 1976, and allowed considerable labour savings at that time. 

See also Voltammetry Anodic Stripping Cathodic Stripping. 

See also Polarography Overview Techniques Organic Appiications. Voltammetry Overview Linear Sweep and Cyciic Anodic Stripping Cathodic Stripping Inorganic Compounds. 

See also Voltammetry Overview Anodic Stripping Cathodic Stripping inorganic Compounds Organic Compounds. 

The CSCs are trapezoidal shaped multiwire proportional chambers which consist of 6 anode wire planes crossed with 7 copper strips cathode panels in a gas volume. They provide a two-dimensional position measurement, where the r and (p coordinates are determined by the copper strips and the anode wires, respectively. The muon detector endcaps consist of 4 CSC stations on each side and identify muons in the pseudorapidity range of 0.9 < V < 2.4. 

This enables traces as low as 10 M to be determined. With the square-wave polarograph, concentrations one order lower can be analysed. The most sensitive method as yet seems to be the method of anodic stripping . In this method reduction products can be formed at the surface of the electrode and then stripped anodically. The anodic current corresponding to the dissolution process is either followed polarographically or with an oscilloscope. Similarly oxidizable substances can be stripped cathodically. These methods enable polarographically active substances to be detected in 10 or even 10 M solutions. )... 

Stripping Voltammetry One of the most important quantitative voltammetric techniques is stripping voltammetry, which is composed of three related techniques anodic, cathodic, and adsorptive stripping voltammetry. Since anodic strip-... 

Anodic stripping voltammetry consists of two steps (Figure 11.37). The first is a controlled potential electrolysis in which the working electrode, usually a hanging mercury drop or mercury film, is held at a cathodic potential sufficient to deposit the metal ion on the electrode. For example, with Cu + the deposition reaction is... 

The experimental design for cathodic stripping voltammetry is similar to that for anodic stripping voltammetry with two exceptions. First, the deposition step in-... 

Anodic Stripping Voltammetry Cathodic Stripping Voltammetry Absorptive Stripping Voltammetry... 

Second, stripping is accomplished by scanning cathodically toward a more negative potential, reducing Hg2 back to Hg and returning the analyte to solution. 

Table 11.11 lists several analytes that have been analyzed successfully by cathodic stripping voltammetry. 

In adsorptive stripping voltammetry the deposition step occurs without electrolysis. Instead, the analyte adsorbs to the electrode s surface. During deposition the electrode is maintained at a potential that enhances adsorption. For example, adsorption of a neutral molecule on a Hg drop is enhanced if the electrode is held at -0.4 V versus the SCE, a potential at which the surface charge of mercury is approximately zero. When deposition is complete the potential is scanned in an anodic or cathodic direction depending on whether we wish to oxidize or reduce the analyte. Examples of compounds that have been analyzed by absorptive stripping voltammetry also are listed in Table 11.11. 

This experiment describes the application of cathodic stripping voltammetry to the analysis of Ni and Co in fresh water and sea water. 

Thioamide drugs, such as that shown here, can be determined by cathodic stripping analysis. Deposition occurs at +0.05 V... 

Caustic Soda. Diaphragm cell caustic is commercially purified by the DH process or the ammonia extraction method offered by PPG and OxyTech (see Fig. 38), essentially involving Hquid—Hquid extraction to reduce the salt and sodium chlorate content (86). Thus 50% caustic comes in contact with ammonia in a countercurrent fashion at 60°C and up to 2500 kPa (25 atm) pressure, the Hquid NH absorbing salt, chlorate, carbonate, water, and some caustic. The overflow from the reactor is stripped of NH, which is then concentrated and returned to the extraction process. The product, about 62% NaOH and devoid of impurities, is stripped free of NH, which is concentrated and recirculated. MetaUic impurities can be reduced to low concentrations by electrolysis employing porous cathodes. The caustic is then freed of Fe, Ni, Pb, and Cu ions, which are deposited on the cathode. 

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